**Author details**

its host, especially in the production of metabolites that are active against a narrow spectrum and a broad spectrum of invasive pathogens. Nanotechnological and genetic engineering approaches could widen the precision and spectrum of activity of bacteriocins in future, making them the next generation of antimicrobials [71]. If these products can be utilized, they can effectively guard against antimicrobial resistance (in addition to the maintenance of gut microbial homeostasis) and can serve as therapeutic alternatives in the treatment of inflammatory bowel diseases, irritable bowel syndrome, colorectal cancer, and extra-intestinal diseases such as diabetes. Scientists believe that probiotics will replace antibiotics as drugs vetted by the FDA and European regulatory bodies in the nearest future. This laudable goal is dependent on the correct identification of probiotic strains (with the aid of next-generation sequencing technologies), the palatability of these strains to the sensory organ, validated storage and transport of intact cells to the gut (via microencapsulation approaches, or functional foods, and the fulfillment of all requirements and validation of all necessary stages for its

There is also a proposal that gut microbes can be genetically engineered so that they possess characteristics that detect what food is present in the gut, monitor inflammation, detect and fight against gastrointestinal pathogens thereby reducing reliance on antibiotics, and exert extra-intestinal effects such as the regulation of behavior and mood and treatment of cancer [73]. Genetically engineered microbes have been reported to be effective against *Vibrio cholerae* in mice especially when this pathogen was ingested 8 hours after the administration of the genetically engineered microbe [74]. There are still many ongoing trials seeking to manipulate and monitor the activities of genetically-engineered microbes in the gut, albeit in animal models. These microbes have to be tested for their safety and their ability to be fit enough to endure gastrointestinal conditions (stomach acid and bile) and successfully colonize the host's gut [75]. There is also the fear about the effect of horizontal recombinant gene transfer on the natural gut commensals. Although microbiome engineering is challenging, it is expected that this strategy will be less expensive and more effective than the traditional methods of gastrointestinal and other extra-intestinal disease control if achieved [76]. The major goal of genetic

One of the most effective ways to reduce the abundance of multi-drug resistant pathogens is with the use of beneficial microorganisms and/or their metabolites, analogous to the effective environmentally-friendly biological method of eliminating stubborn pests in farmlands by agriculturalists. The benefits of the gut microbiota are being constantly unraveled as advanced next-generation sequencing techniques arise. The field of microbio-therapeutics is steadily growing. Harnessing the potentials of these microbes is paramount to making the world a

manipulation of gut microbes is to improve the health of humans.

approval as a new drug [72].

124 Antimicrobial Resistance - A Global Threat

**8. Conclusions**

healthier and better place to live.

The authors declare that there is no conflict of interest.

**Conflict of interest**

Ayorinde O. Afolayan, Adewale Adetoye and Funmilola A. Ayeni\*

\*Address all correspondence to: funmiyeni@yahoo.co.uk

Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Ibadan, Ibadan, Nigeria
